use doubles for startTime and endTime

don’t lose precision by doing integer arithmetic
node-inspector · Jul 29, 2015 · ac3424f · ac3424f
1 parent ed5b7ce
commit ac3424f
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/src/cpu_profile.cc b/src/cpu_profile.cc
@@ -82,8 +82,8 @@ namespace nodex {
     profile->Set(NanNew<String>("head"),      head);
 
 #if (NODE_MODULE_VERSION > 0x000B)
-    Local<Value> start_time = NanNew<Number>(node->GetStartTime()/1000000);
-    Local<Value> end_time = NanNew<Number>(node->GetEndTime()/1000000);
+    Local<Value> start_time = NanNew<Number>((double)node->GetStartTime()/1000000.00);
+    Local<Value> end_time = NanNew<Number>((double)node->GetEndTime()/1000000.00);
     Local<Array> samples = NanNew<Array>();
 
     uint32_t count = node->GetSamplesCount();

diff --git a/test/cpu_cprofiler.js b/test/cpu_cprofiler.js
@@ -67,6 +67,17 @@ describe('CPU', function() {
       expect(profile.samples.length > 0).to.equal(true);
     });
 
+    it('should record startTime and endTime with subsecond precision', function(done) {
+      profiler.startProfiling('P');
+      var delayInMilliseconds = 150;
+      setTimeout(function() {
+        var profile = profiler.stopProfiling();
+        var elapsedTime = profile.endTime - profile.startTime;
+        expect(elapsedTime).to.be.at.least(delayInMilliseconds / 1000);
+        expect(elapsedTime).to.be.at.below(3 * delayInMilliseconds / 1000);
+        done();
+      }, delayInMilliseconds);
+    });
   });
 
   describe('Profile', function() {